>>149445547
>You take photos of your coworkers and edit them at home?

Dude is a photographer with 2 jobs: 1: take photos of superman, and 2: bring coffee to Perry, while doing so passing by Clark's desk several times a day. At that point it's just putting 2+2 together - same way how Mysterio figured out Spidey's identity, that of Mary Jane Watsons husband.

There's AT LEAST one continuity I remember where Jimmy specifically figured out Supermans identity on his own (he also states "which bored photographer didn't drew glasses on the faces on his photos"), and I don't even read or watch DC a lot.